There is more of a diff in barrel length and velocity in centerfire rifles. Then in some cases that is a myth. If you hand load the type of powder you use may determine big changes in speed. Some powders burn faster and then a short barrel might be fine. Of course some powders are slow burning and hence need a longer barrel For hunting I don't believe it matters. The fastest load for my custom 220 swift is one of least accurate loads. IMHO in ML's it don't matter. Like Sabotlaoder says his Rem 700 is almost identical in his eyes to his longer barreed ML. Its all about marketing I think.